1. Technical Field
The present invention relates to bidirectional communication between hand-held units (HHUs) and in-vehicle units (IVUs), and more particularly, to an IVU communication protocol.
2. Discussion of the Related Art
When communicating between a hand-held unit (HHU) such as a two-way remote transmitter and an in-vehicle unit (IVU) such as a vehicle control system, once an inbound message from the HHU is received by the IVU, response data is sent from the IVU to the HHU in a bundle after a predetermined time out. Generally, this time out takes about two to five seconds. IN addition, the response data is generally sent from the IVU for about five to ten seconds. This is done to improve the chances of the HHU receiving the response data.
However, during the time in which the response data is sent to the HHU, no other inbound messages can be received by the IVU. Further, since the response data is set for such a long time, there is a perceivable delay in actions performed by the vehicle and feedback reaction to the HHU. Accordingly, there is a need for a technique of reducing the amount of time it takes to send response data from an IVU to an HHU so that there is essentially no perceptible delay in actions performed by the vehicle and feedback reaction by the HHU.